Electrical ground-detector.



H. W. BROWN. ELECTRICAL GROUND DETECTOR.

APPLICATION FILED OCT. 17, 1912.

Patented 001;. 6. 1914.

BY w %u/ ATTORNEY gm s: @Mn

HARC'LD nensia F PENNSY ASSIGNQE T0 VIESTZNG- CGRPORATION OF PENN- ELECTRICAL GEGUND-IITITECTORV :cse'ceof grounds on electrilug cir'. object to provide a ground detector which sh torque so that it Will'be no ire in opera tion, and which may be adapted with tle or no :0 for use upon any circuit.

voltage and W l a-i163. it or direct current igure 1 o, a face new; of in accor of the instrunie a lo" showing ie a is BIllPl voltage cum tion with a high tions 7 angles thereto. The arn'u... n'iagnetizalile be is upon the ooposite ends of which llQiiC mounted, the heads 1 sent polar faces ad l" i ing: re rely to 3 and 4;.

" be capable heads are laped to precorres mnd: ar projections mounted so as to in any direction from its normal p ion, as shown in the 5?: drawing, and to this end the bar 14; com- Lication of I.- tters Patent unia have ion relates to means for de-' and ithas for its nple and econonncal all have a large.

l l i i l Serial No. 726,280.

r vuricunds and is pivotally connected to heft 17 having bear- Iings at its ends in a stationary yoke or racket 19. The cross bar 141 of the arma ture surrounded by two spaced coilsfi20 that are located upon onposite sides of the waft 17, and are also supported by the yoke or bracket "he said C-OllS being thus stationarily inounte l. The openings through I the coils however, are of suflicient diameter i to permit of entire freedom of movement of Z the said bar, and the spaces between the l abutting faces of the coils are also sufiicient to permit of freedom of rotation of the i shat}; 1.7. 1 When the instrument is employed in c0ni nection with a low voltage circuit, the connections are a shown in Fig. in which i ter inals coils G and T are re- 1 suew irel g connected directly to distributing conductors and 2i, and the res at the said-coils are on- Jul to one terminal of the v nectcd V ietizing' for the armature, the

which connected to the .l cozuiitions. with this arranger cue. {he ccnnections, substantiall equal currents traverse the coils 5., 6 and T from the distributing circuit grcund. r

the coil Y. This resul accordingly, moves in a direction to indicate that the conductor 2 is connected to the ground.

In Fig. 4, transformers 26. Q7 and 28 respectively are interposed between the ground detector and the distributing circuit 29-30-3l tor the purpose of reducing to ii safe Value the potential upon the terminals of the instrument, the corinnon or neutral terminal. of both the primary; and

in an unlmlancing or the torques upon me miniature, which,

Th ingtl'ul'ne, comprises 3 through the coils 20 to the ground, and the laminated core me" A nal ire consequently remains in a central tially cquulf spaced position lioueveiytliegroundingohm y one dial polar prnjectio of the distributing circuit conductors will rerounded espectire V suit in uncquai lions ot rurrcnt through the 3 The cor member .7 coils 7r. 6 and 7, followed by a movement of manner to a plate or the armature in a direction corresponding turn. secured to the back and indicative of. the grounded conducing l0 that incloscs til will be. undcrslood assuming tire instrument and is 'ound occurs upon the comluctor 24, i in wlnci case cmemw currents will traverse and to the common terminal of the second- 1 ground occurs upon one of the distributing ary windings of the transformer. 1i, when the connections are as shown in Fig. 4, a

circuit conductors, unequal currents will 'traversethe primary windings of the transformers, and also the secondary windings, with the result that the armature of the ground detector is inoved in a direction to indicate the grounded conductor, in a similar manner, to that. set forth in connection ,with' Fig. 3.

By reason ofthe fact that the operating torque of the instrument is produced by electrical magnet windings, and that each of the said windings is provided with ama gnetizable core, it will be readily understood that the torque is high and may be made sufiicient; to effect positive and reliable move ments of the armature. The instrument also permits of the employment of transformers when it is used in connection with an alternating current circuit and accordingly may be ada )ted for use with circuits of any vpltage, w ile, at the same time, the voltage upon the terminals of the instrument may be relatively low, so that there is no danger to operators while the instrument is in use, and

no diificulties are experienced in providing" adequate insulation. Moreover, the degree of movement of the armature'indicates quite accurately the voltage between the grounded conductor and the ground, and thus obviates the necessity of employing a separate voltmeter "for obtaining this information.

I claim as my invention:

'1. A ground *detector' comprising relatively universally movable members, one of which is provided with a lurality of coils having a common terminzH, and the "other of which is provided with acoil that is connected to the common terminal of the aforesaid coils'.

2. A ground detector comprising relatively universally movable members, one of which is'provided with a plurality of coils having a common terminal, and the other of which is provided with a coil that is connected between thesaid commonte'rminal and the ground.

3. The combination with a distributing circuit, of a ground detector com rising reh atively universally movable mem ers, one of which is provided with a plurality of coils having a common terminal and the remain- 4;. The combination with a distributing circuit of a ground detector, comprising relatively universally movable members, one of which is provided with a plurality of coils respectively corresponding to and associated with the distributing circuit conductors, the said coils having a common terminal, and the other member of which is provided with a coil that is connected to the common terminal of the aforesaid coils.

5." The combination with a distributing circuit of a ground detector, comprising relatively universally movable members, one .of which is provided with a plurality of coils respectively corresponding to and associated with the distributing circuit conductors, the said coils havinga common terminal, and the other member of which is provided with a coil that is connected between the common terminal of the aforesaid tionary member provided with a plurality of field coilshaving a common terminal,a universally movable armature within the mag netic field of the'said coils, and a stationary magnetizing coil for the armature that is connected to the common terminal of the aforesaid coils. a 8. A ground detector comprising a stationary mem-her provided with a plurality of field coils having a common terminal, a universally movable armature within the magnetic field of the said coils, and a stationary, magnetizing coil for the armature that is connected between the common terminal of the aforesaid coils and the ground. 9. A ground detector comprising a core member having a plurality of opposing polar projections, a coil upon each of the said projections, a universally movable-air mature within the magnetic fields of the said coils, the polar axis of the armature being normally disposed transversely to the polar member having a plurality of axes of the polar projections from the core, and a stationary magnetizing coil for the armature.

11. A ground detector comprising a core opposing polar projections, a coil upon each of the said projections, a universally movable armature within the magnetic fields of the said coils, each pole of the armature comprising as many branches as there are poles upon the core, and a stationary magnetizing coil for the armature.

12. A ground detectm' comprising relatively movable members, one of which is provided with a plurality of coils having a common terminal, and the other of which is provided with a. coil that is connected to the common terminal or the aforesaid coils the Fluxes produced by the said coils cooperatl l l l l l l l ing to produce relative movement of the said members.

13. A ground detector comprising relatively movable members, one of which is provided with a plurality of coils having a common terminal, and the other of which is provided with a coil that is connected between the said common terminal and the ground, the fluxes produced by the said members cooperating to produce relative movement of the said member".

In testimony whereof, I have hereunto subscribed my name this 27th day of Sept. 1912.

HAROLD \V. BROl/VN.

lVitnesses B. B. Hines,

13. ll. SMITH. 

